难难难！Graphics2D搞死我了

Question

写错了！是JComponent子类， 而不是Component子类
补充一个例子:import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;public class Ex extends JApplet implements ActionListener
{
private JButton proper = new JButton("Proper");
private JButton improper = new JButton("Improper");
private JPanel ButtonPanel = new JPanel();
private JFrame properFrame;
private JFrame improperFrame; public void init()
{ properFrame = new MyFrame("Proper");
improperFrame = new MyFrame("Improper");
proper.addActionListener(this);
improper.addActionListener(this);
getContentPane().add(ButtonPanel); ButtonPanel.add(proper);
ButtonPanel.add(improper);
}
public void actionPerformed(ActionEvent evt)
{
Object Source = evt.getSource();
if (Source == proper)
{
if(!properFrame.isVisible())
properFrame.show();
}
else if (Source == improper)
{
if(!improperFrame.isVisible())
improperFrame.show();
} }}class ProperPanel extends JPanel
{
public ProperPanel()
{
setPreferredSize(new Dimension(800,600));
}
public void paintComponent(Graphics g)
{
super.paintComponent(g); Graphics2D g2d = (Graphics2D)g;
g2d.fillRect(100,100,100,100);
}
}class ImproperPanel extends JPanel
{
public ImproperPanel()
{
setPreferredSize(new Dimension(800,600));
} public void paintComponent(Graphics g)
{
super.paintComponent(g); Graphics2D g2d = (Graphics2D)g; //*********************************************************
g2d.setTransform(AffineTransform.getScaleInstance(1f,1f)); //The reason about the problem!!!
//********************************************************* g2d.fillRect(100,100,100,100);
}
}class MyFrame extends JFrame
{
private JPanel MyPanel;
private JScrollPane sp; public MyFrame(String cl)
{ setSize(500,400); if (cl == "Proper")
{
setTitle("Proper frame");
MyPanel = new ProperPanel();
}
else if(cl == "Improper")
{
setTitle("Improper frame");
MyPanel = new ImproperPanel();
}
sp = new JScrollPane(MyPanel);
getContentPane().add(sp,"Center");
}
}

Answer 1

class ImproperPanel extends JPanel
{
 boolean firstTime = true; public ImproperPanel()
 {
  setPreferredSize(new Dimension(800,600));
 }
 
 public void paintComponent(Graphics g)
 {
  super.paintComponent(g);
 
  Graphics2D g2d = (Graphics2D)g;
 
  if (firstTime) {
    firstTime = false;
  //*********************************************************
    g2d.setTransform(AffineTransform.getScaleInstance(1f,1f)); //The reason about the problem!!!
  //*********************************************************
  } 
  g2d.fillRect(100,100,100,100);
 }
}

Answer 2

这样不行，setTransform跟本没起作用

Answer 3

你难道不是做的变形转换吗？java教程中有例子。

Answer 4

我是做transform但java教程中的例子没有将其包含有JScrollPane中
不过我已有办法解决了，就是用transform()替代setTransform().